Roaming is a key technique in wireless local area networks (WLANs) and is an important basis for a wireless terminal to achieve mobility. At present, mainstream WLAN networking techniques include an access controller (AC) and a Fit access point (AP). A Fit AP provides wireless encryption while using the AC for the actual key exchange. Under this technique, the manner in which seamless roaming for a wireless client (STA) is performed and in particular, how roaming of STA's between different ACs is performed is an index that is used to evaluate the performance of a wireless device.